The participation of an e-notary, acting as an on-line Trusted Third Party is required in some scenarios, such as Business to Business, Intellectual Property Rights contracting, or even as a legal requirement, in contract signing is frequently necessary. This e-notary gives validity to the contract or performs some tasks related to the contract, e.g. contract registration. In the abovementioned contracting scenarios, two important additional features are needed: the negotiation of the e-contract and confidentiality. However, until now, e-contract signing protocols have not considered these issues as an essential part of the protocol. In this paper, we present a new protocol which is designed to make negotiation and contract signing processes secure and confidential. Moreover, compared to other previous proposals based on an on-line Trusted Third Party, this protocol reduces the e-notary’s workload. Finally, we describe how the protocol is being used to achieve agreements on the rights of copyrighted works.

fair exchange, contract signing protocol, Intellectual Property Rights contracts, secure negotiation, confidentiality